In the present study, we have selected Ba6Ti5O18 ceramics belonging to cation deficient perovskite family keeping in view their promising microwave dielectric properties like high dielectric constants, good quality factors and thermal stability. All these characteristics make these cation deficient perovskite ceramics, the useful materials for fabrication of dielectric resonators that are essential part of Microwave Communication Technology. By close inspection and critical analysis of the results of substitutional studies performed on various compounds of Barium Titanate family, zirconium has been chosen as a dopant on titanium site as its addition to barium titanates causes change in curie temperature, noticeable decrease in dielectric maxima, formation of core shell grains leading to desired temperature stability of dielectric properties and enhancement in dielectric properties with minimal impact on the crystallographic chemistry of these compounds. Here, we have synthesized Ba6(Ti1-xZrx)5O18 (0